A laboratory investigation was conducted to evaluate the effects of a few promising modifiers on the long-term aging characteristics of typical asphalt cements and asphalt concrete mixtures used in Florida. The seven types of modifiers evaluated in this study include (1) gilsonite, (2) carbon black, (3) fine ground tire rubber (GTR-80), (4) coarse ground tire rubber (GTR-40), (5) styrene-butadiene rubber (SBR), (6) ethylene vinyl acetate (EVA), and (7) styrene-ethylene-butylene-styrene (SEBS). These modifiers were blended with an AC-30, AC-20, and AC-5 to produce various modified asphalts for this study. The results of the study indicate that the addition of modifiers generally reduces the rate of aging of the asphalts. AC-30 asphalt appears to be too hard and AC-5 asphalt appears to be too soft for use in modified asphalts in Florida. A more effective grade of asphalt to be used for this purpose appears to be somewhere in between these two grades. The laboratory aging processes of the TFOR, RTFOT, California tilt over and SHRP PAV appear to simulate the field aging process quite adequately as seen from the similar rheological properties of the aged asphalt binders. The RTFOT is found to be a more severe aging process than the TFOT as seen from the percent penetration retained and absolute viscosity ratio of the aged modified asphalts. The RTFOT is found to be not suitable for use on the coarse ground tire rubber modified asphalts because the modified asphalt binders tend to spill out from the bottle during the RTFOT process. Skin formation tends to occur on the surface of certain modified asphalts during the TFOT process.

  • Supplemental Notes:
    • University of Florida Project No. 4910450431912.
  • Corporate Authors:

    University of Florida, Gainesville

    Engineering and Industrial Experiment Station
    Gainesville, FL  United States  32611

    Florida Department of Transportation

    Haydon Burns Building, 605 Suwanee Street
    Tallahassee, FL  United States  32301

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • Tia, M
    • Ruth, B E
    • Huang, S-C
    • Chiu, C-T
  • Publication Date: 1994-11


  • English

Media Info

  • Features: Figures; Photos; References; Tables;
  • Pagination: 259 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00670412
  • Record Type: Publication
  • Report/Paper Numbers: FL/DOT/RMC/0516-3532, State Proj 99700-7387-119, WPI 0510516
  • Contract Numbers: C3532, 0516
  • Created Date: Dec 14 1994 12:00AM